Washington Redskins quarterback Kirk Cousins congratulates wide receiver Leonard Hankerson after a 54-yard touchdown pass in the first quarter of an NFL football game against the Cleveland Browns in Cleveland, Sunday, Dec. 16, 2012. / Rick Osentoski, AP

by John Perrotto, Special for USA TODAY Sports

by John Perrotto, Special for USA TODAY Sports

CLEVELAND -- There likely always will be concerns about Robert Griffin III's durability.

A large part of RGIII's appeal is his willingness to try to make something out of nothing by scrambling out of the pocket and taking off on a run. Often the Washington Redskins rookie sensation will sacrifice his body for a couple of extra yards, which makes him more susceptible to injury than most quarterbacks.

However, the Redskins can take comfort in knowing that they can win without Griffin.

Fellow rookie quarterback Kirk Cousins made his first start Sunday while Griffin with sidelined with a sprained right knee and turned in an impressive performance in leading the Redskins to a 38-21 victory over the Cleveland Browns.

Cousins, the Redskins' fourth-round draft pick this year from Michigan State, threw for 329 yards and two touchdowns, both to Leonard Hankerson. Cousins completed 26 of 37 passes and overcame an early interception to lead the Redskins into a share of first place in the NFC East with the Giants and Cowboys.

The previous Sunday, Cousins came on in relief for the injured Griffin late in the fourth quarter and rallied the Redskins to a 31-28 victory over the Baltimore Ravens.

"I had all the faith in the world in Kirk, so I never doubted him at all," said Alfred Morris, yet another Redskins' rookie, who rushed for 87 yards and two touchdowns. "Everyone in this locker room knows what Kirk can do."

Still, it's one thing playing part of a game and something entirely different to play a full 60 minutes. Cousins showed he was more than up to the challenge after a shaky start in which he misfired on his first three passes and was intercepted on the Redskins' second possession.

"It show you what the guy's all about, the way he kept his composure," Redskins coach Mike Shanahan said. "That one throw (on the interception), I thought there was a little shoving right there. I thought he made the correct read but those things happen sometimes. You have to keep your composure and fight through it."

Cousins did that and once he got rolling there was little the Browns could do to stop him as the Redskins took control of their own playoff destiny with their fifth in a row, their longest winning streak in seven years.

If the Redskins win their final two games -- at Philadelphia on Dec. 23 and home against Dallas on Dec. 30 -- they will win the NFC East and qualify for the playoffs for the first time since 2007.

"This isn't my first rodeo," Cousins said. "I did play a lot of football in the Big Ten. I had games like that where I started slow. You've got to have character. You've got to find it in yourself to dig deep and keep pushing and that's what we did. And that's what I'm proud of my team for the way we didn't get spooked by a slow start. We got a good tempo going, we found a rhythm and it made all the difference."

Cousins isn't nearly as mobile as Griffin -- then again, few quarterbacks are -- so the Redskins didn't use any option plays Sunday. However, Washington didn't alter its offense in any other way with Cousins at quarterback and he showed good mobility on both touchdown passes.

While on the run, Cousins threaded a pass through three defenders to Hankerson for a 54-yard touchdown late in the first quarterback that tied the score at 7-7. In the third quarter, Cousins rolled right on a play-action pass and threw a 2-yard strike to Hankerson that put the Redskins in front, 24-14.

"I think as much as Robert wants to show people he can be a pocket passer, which he can, I want to show people that I can move around a little bit and I think I did that today," Cousins said. "We both have our strengths and our coaches are going to try and utilize us the best they can."

Throughout the week, Shanahan left open the possibility that Griffin could play. The Redskins did not officially name Cousins as the starter to Saturday after the Browns had already finished preparations for the game.

However, Browns coach Pat Shurmur dismissed the idea that Cousins' success might have partially been due to the element of surprise.

"They would have been doing all the same things, with the addition of the option if RGIII was in the game," Shurmur said. "That looked like the Redskins' offense. I'd like to credit Kirk. I thought he did a nice job of playing the game. He led his team to victory."